Single layer, multi-channel band-gear system for rotary joint

Abstract

A multi-channel band-gear system for a rotary joint has a ring gear assembly with a conducting ring band in electrical contact with corresponding conducting bands of a set of intermediary planetary gears, which in turn are in electrical contact with a conducting sun band of a sun gear assembly. The ring band is formed with a plurality of conducting segments which are electrically insulated from each other and positioned angularly in a circumferential direction of the ring gear, such that separate electrical power/signal channels are formed across the rotary joint. In a preferred embodiment having continuously connected channels, the ring band has four conducting segments at 90° intervals, the sun band has two conducting segments at 180° intervals, and three planetary bands are in rolling electrical contact at 120° intervals between the ring band segments and the sun band segments, forming two continuously connected channels in a single layer of the band-gear system. Multiple sets of ring gear, planetary gear, and sun gear assemblies may be used in a stacked configuration in a single axial layer to further increase the number of channels provided through the band-gear system.

I claims: 
     
       1. A multi-channel band-gear system comprising: a ring gear assembly having a conducting ring band mounted concentrically therewith;   a set of intermediary planet gear assemblies each having a conducting planetary band mounted concentrically therewith; and   a sun gear assembly having a conducting sun band mounted concentrically therewith,   wherein the planetary bands of the planetary gear assemblies are in rolling electrical contact between the ring band of the ring gear assembly and the sun band of the sun gear assembly, and   wherein the ring band is formed with a first plurality of conducting segments which are electrically insulated from each other and positioned angularly in a circumferential direction of the ring band so as to form a multiplicity of electrically connected channels through the ring, planetary, and sun bands of the band-gear system,   wherein said ring band has four conducting segments arranged at 90° intervals and electrically insulated from each other, said sun band has two conducting segments arranged at 180° intervals in alignment with the ring band segments and electrically insulated from each other, and three planetary bands are provided in rolling electrical contact at 120° intervals between the ring band segments and the sun band segments, and wherein each two opposed ring band segments are paired together and at least one planetary band is in rolling electrical contact between each pair of ring band segments and a corresponding one of the sun band segments at all times, so that two continuously connected channels are provided in a single layer of the band-gear system.   
     
     
       2. A multi-channel band-gear system according to claim 1, wherein said sun gear assembly is mounted to a rotary shaft on a center axis of the band-gear system. 
     
     
       3. A multi-channel band-gear system according to claim 1, further comprising additional stacked sets of ring gear, planetary gear, and sun gear assemblies for increasing the number of channels provided in the band-gear system. 
     
     
       4. A multi-channel band-gear system according to claim 3, wherein the first-mentioned ring gear, planetary gear, and sun gear assemblies constitute an inner first set of assemblies, further comprising an intermediate second set of ring gear, planet gear, and sun gear assemblies in geared engagement with the assemblies of the first set, and a third set of ring gear, planet gear, and sun gear assemblies in geared engagement with the assemblies of the second set. 
     
     
       5. A multi-channel band-gear system according to claim 4, wherein four continuously connected channels are provided through the ring, planetary, and sun bands of the three sets in a single layer of the band-gear system.